Method for producing a package-type semiconductor assembly

Abstract

In production of a closed package-type semiconductor assembly provided with a built-in semiconductor element and conductive leads for connection to outside devices, a conductive island, the conductive leads and other accessories are united together by one stage moulding of molten glass. Simple process reduces the production cost greatly and no use of dusty ceramic components much raises functional reliability of the product.

We claim: 
     
       1. A method for producing a package casing for a package-type semiconductor assembly comprising the steps of: providing at least one straight conductive lead having inner and outer lead sections and first and second lead surfaces;   providing a first mold having first and second end surfaces and a cavity open in the first and second end surfaces;   providing a second mold having first and second end surfaces and a cavity open in the first and second end surfaces of said second mold;   combining said first and second molds together in a manner such that said at least one conductive lead is clamped between said first surfaces of said first and second molds with said inner lead section being exposed in said cavities of said first and second molds and said first lead surface facing said cavity in said first mold and said second lead surface facing said cavity in said second mold;   inserting a first plunger into said cavity in said first mold to a first position spaced from said first lead surface of said inner lead section of said at least one conductive lead to provide an upper space;   inserting a second plunger into said cavity in said second mold to a position in contact with said second lead surface of said inner lead section of said at last one conductive lead;   providing a lower space between said second mold, said second plunger, and a portion of said second lead surface of said at least one lead adjacent said second end surface of said second mold;   placing at least one conductive island in said cavities in adjacent spaced relation to said inner lead section of said at least one conductive lead;   partly filling glass powder into said upper and lower spaces in said cavities of said first and second molds;   melting said glass powder by application of heat;   forcibly moving said first plunger in said cavity in said first mold to a second position closer to but spaced from said first surface of said inner lead section of said at least one conductive lead so that molten glass completely fills said spaces in said cavities; and   solidifying said molten glass by cooling to integrate said inner lead section of said at least one conductive lead and said conductive island in adjacent spaced relation in a unitary glass body.   
     
     
       2. A method for producing a package casing for a package-type semiconductor assembly comprising the steps of: providing at least one straight conductive lead having inner and outer lead sections and first and second lead surfaces;   providing a first mold having first and second end surfaces and a cavity open in the first and second end surfaces;   providing a second mold having first and second end surfaces and a cavity open in the first and second end surfaces of said second mold;   combining said first and second molds together in a manner such that said at least one conductive lead is clamped between said first surfaces of said first and second molds with said inner lead section being exposed in said cavities of said first and second molds and said first surface facing said cavity in said first mold and said second lead surface facing said cavity in said second mold;   inserting a first plunger into said cavity in said first mold to a first position spaced from said first lead surface of said inner lead section of said at least one conductive lead to provide an upper space;   inserting a second plunger into said cavity in said second mold to a position in contact with said second lead surface of said inner lead section of said at last one conductive lead;   providing a lower space between said second mold, said second plunger, and a portion of said second lead surface of said at least one lead adjacent said second end surface of said second mold;   partly filling glass powder into said upper and lower spaces in said cavities of said first and second molds;   melting said glass powder by application of heat;   forcibly moving said first plunger in said cavity in said first mold to a second position closer to but spaced from said first surface of said inner lead section of said at least one conductive lead so that molten glass completely fills said spaces in said cavities; and   solidifying said molten glass by cooling to integrate said inner lead section of said at least one conductive lead in a unitary glass body.   
     
     
       3. A method as claimed in claim 1 wherein: said glass powder is in the form of fine particles.   
     
     
       4. A method as claimed in claim 1 wherein: said glass powder is in the form of incompletely sintered small pieces.